1. Department of Chemistry and Biochemistry, San Diego State University, 5500 Campanile Drive, San Diego, CA 92182‐1030, USA, http://www.chemistry.sdsu.edu/
2. Department of Chemistry, The University of Alabama, Tuscaloosa, AL 35487‐0209, USA, http://www.bama.ua.edu/~chem/people/faculty/papish/papish.html
3. Previous address: Department of Chemistry, Drexel University, 3141 Chestnut Street, Philadelphia, PA 19104, USA
4. Department of Chemistry, Villanova University, 800 Lancaster Avenue, Villanova, PA 19105, USA, http://www1.villanova.edu/villanova/artsci/chemistry.html
5. Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093‐0385, USA